Biological Basis of Behavior
Mohamed Ahmed Abd El-Hay in Understanding Psychology for Medicine and Nursing, 2019
A strand of DNA serves as a template for the synthesis of ribonucleic acid (RNA) molecules. There are four types of RNA, each encoded by its own type of gene. Messenger RNA serves as a template for the synthesis of protein molecules. DNA contains four bases (adenine, guanine, cytosine, and thymine). The order of those bases determines the order of corresponding bases along an RNA molecule (adenine, guanine, cytosine, and uracil). In turn, the order of bases along an RNA molecule determines the order of amino acids that compose a protein, e.g., if three RNA bases are, in order, cytosine, adenine, and guanine, then the protein adds the amino acid glutamine. If the next three RNA bases are uracil, guanine, and guanine, the next amino acid on the protein is tryptophan. In total, proteins consist of 20 amino acids, and the order of those amino acids depends on the order of DNA and RNA bases.
Introduction to Cells, DNA, and Viruses
Patricia G. Melloy in Viruses and Society, 2023
Before learning about viruses, it is useful to understand what they infect: our cells. It has been known for quite some time that our bodies are made of cells. Going back to the early 1800s, Matthias Schleiden and Theodor Schwann determined that all animals and plants are made of cells. Cells are defined philosophically as being the fundamental units of life and are distinctive for being able to reproduce themselves to make other cells. All these ideas (animals and plants are made of cells, cells are the fundamental units of life, cells give rise to other cells) put together became what is now called the cell theory (Alberts et al. 2019). From the point of view of chemical content, one can also define cells as containing many macromolecules needed for the processes of life, protected by the cell membrane. Although our cells are mostly made of water, the key macromolecules present are critical for cellular function, including nucleic acids, carbohydrates, proteins, and lipids. DNA and ribonucleic acids (RNA) are nucleic acids, made of building blocks called nucleotides. Proteins are made of amino acids. Carbohydrates are made of sugar subunits. Lipids, also known as fats, are made of fatty acids and glycerol. See Table 1.1 for key definitions.
Genetics and exercise: an introduction
Adam P. Sharples, James P. Morton, Henning Wackerhage in Molecular Exercise Physiology, 2022
How is a gene “read” to produce a protein? Francis Crick wrote in 1956 something in his notebook which he called the “central dogma”. Today, this unpublished notion is widely known as the central dogma of molecular biology. It describes how the biological information flows in the “DNA → RNA → protein” direction. According to the dogma, DNA is equivalent to the instructions for the book of life. RNA is very similar to DNA, but it is single-stranded, whereas DNA is double-stranded (i.e. the double helix), and the sugar in RNA is a ribose, whereas the sugar in DNA is a deoxyribose. Also known as “messenger” RNA (mRNA), the RNA copies and delivers the DNA “message” to the protein-making machinery of the cell (in the ribosome) to make the protein. The making or synthesis of RNA from DNA is termed transcription (RNA synthesis also described as gene expression) and the process of protein synthesis from RNA is termed translation. Figure 3.7 illustrates Crick’s central dogma. It is important considering recent advances in molecular biology to recognise that the central dogma is incomplete and that there are exceptions to the dogma.
siRNA: an alternative treatment for diabetes and associated conditions
Published in Journal of Drug Targeting, 2019
Ribonucleic acid (RNA) consists of a single stranded linear structure has crucial role in regulation and expression of specific gene and also stores genetic information. RNA structure consists of four ribonucleotide base pairs namely, adenine, guanine, cytosine and uracil in which purines like adenine and guanine binds which complementary pyridines like uracil and cytosine, respectively [8]. RNA is classified into three types, messenger RNA (mRNA), ribosomal RNA (rRNA) and transfer RNA (tRNA) which are involved in protein synthesis in human body, whereas RNA like short interfering RNA (siRNA) and micro RNA (miRNA) are mainly involved in regulation and expression of genes. Both siRNA and miRNA are similar in their structure as well as in their function of silencing and regulation of gene expression by binding with complementary messenger RNA (Figure 2). In contrast, they differ in their mechanism of action and also siRNA targets only one specific mRNA while miRNA has multiple complementary targets [9].
Long non-coding RNA DANCR alleviates hypoxia-caused H9c2 cells damage through up regulation of HIF-1α
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Libin Qiu, Qian Zhao, Lingli Dai, Aoshuang Zhu, Xiaofei Xu, Shanshan Zhao, Jingcheng Chen
In the early days of molecular biology, ribonucleic acid was usually divided into two categories: coding RNA and non-coding RNA [6]. Long non-coding RNA (LncRNA) is a transcription product which is longer than 200 nt but without proteins encoding capabilities [7]. At present, lncRNA has been found to be irreplaceable in other diseases besides its role in the pathophysiology of cancer, such as ischaemic heart disease (containing myocardial infarction and angina pectoris) [8,9]. For example, Li X et al. detected that lncRNA myocardial infarction related transcript 1(Mirt1) was highly expressed in cardiac fibroblasts, and Mirt1 knockdown elevated cardiac roles, reduced cardiomyocytes apoptosis and infiltration of inflammatory cells [10]. Besides that, Gong LC et al. demonstrated that hypoxia induced overexpression of lncRNA H19 and H19 knockdown aggravated hypoxia-caused damage presented as raising cell activity, migration and incursion but reducing cell apoptosis via miR-139-mediated positive regulation of Sox8 [11]. Therefore, in-depth exploration of lncRNAs functions in the occurrence and development of MI as well as the related molecular mechanism are of great significance to the development of molecular targeted drugs, the improvement of therapeutic methods and the increasing of prognosis and survival rate of MI.
Layer-by-Layer technique as a versatile tool for gene delivery applications
Published in Expert Opinion on Drug Delivery, 2021
Dmitrii S. Linnik, Yana V. Tarakanchikova, Mikhail V. Zyuzin, Kirill V. Lepik, Joeri L. Aerts, Gleb Sukhorukov, Alexander S. Timin
Messenger RNA (mRNA) is a biomolecule that mediates the translation of genetic information from genes encoded in DNA to proteins located throughout the cell. The physical and biological characteristics of mRNA allowed its use as a safe genetic material for gene-based therapy approaches, because mRNA, in contrast to DNA, does not require nuclear localization for gene expression and provides rapid protein expression, including in hard-to-transfect cells such as T cells, dendritic cells, and hematopoietic stem cells [102]. Therefore, mRNA is of great interest in immunotherapy application. Development of novel therapeutic methods based on mRNA has been limited due to its instability in ambient conditions. Thus, an intravenous injection of unmodified mRNA without a delivery material leads to rapid mRNA degradation by ribonucleases and can activate the immune system. Viral vectors have been widely used for delivery of mRNA but possess potential immunologic side effects and toxicities. Non-viral strategies such as electroporation, gene gun, and sonoporation offer a better perspective for mRNA delivery, however, they also have certain limitations.